15W-40 or 5W-40 Synthetic?

[Norm Olt]

The manufacturer's plate in the doorsill should list a code as to both the nature of the diff, the axle ratio & whether it is a limited slip.

Cheers!

 

[-SyN-]

Sweet! Thanks Patrick!

 

[Strjock81]

I would be very cautious of adding a chip to the truck without some transmission upgrades. These vehicles are good enough at shredding transmissions without power enhancements. I know someone will come and say that have 1.8 million miles on theirs and haven't had a lick of trouble, but I have had 2 of them myself go early and have a whole host of friends and aquaintances that have also had the same problems, without much if any abuse. The 4r100 is okay but it needs to be beefed up to handle outrageous power long term.

 

[Carpenter58]

I use in my PSD 7.3 Amsoil 5w30 it is a very good 100% synthetic oil. I am thinking of trying the 15w40 though.

Bill

 

[JR]

Also I almost forgot to tell you. Don't forget about the coolant. You should, no I mean you must, use an sca. I would say you should change it, since the last time it was. Use an already precharged coolant, or an HD low silcone coolant and add the proper amount os sca. And you must add a boaster treatment sca dose in it at 15,000 miles. And then change it every 30,000 miles.

 

[-SyN-]

JR: Thanks
I flushed the system about 1 week ago or so.

Put in a good quality Green Coolant and added Napa Kool to the system.

I will change the coolant about every 2 yrs depending on the mileage.

Thanks again: Too all of U.

I will use Delo 400 in the motor until I have to rebuild. Then switch to a Very Good Synthetic.

As for the Rearend and Trans and Transfer Case they all 3 have been flushed out and now flow in Synthetic. Really makes a differance.